Preparation of Ammonia Adsorbent by Carbonizing and Activating Mixture of Biomass Material and Hygroscopic Salt

We put forward a new and ingenious method for the preparation of a new adsorbent by soaking, carbonizing and activating the mixture of hygroscopic salt and biomass material. The new adsorbent has high porosity, uniform distribution and high content of Ca Cl2, and exhibits high adsorption performance. The ammonia uptake and specific cooling power（SCP） at 5 min adsorption time can reach as high as 0.19 g·g^-1 and 793.9 W·kg^-1, respectively. The concept of utilizing the biomass materials and hygroscopic salts as raw materials for the preparation of adsorbents is of practical interest with respect to the potential quantity of biomass materials around the world, indicating that there would be a new market for biomass materials.Key words： biomass material; adsorption system; ammonia; calcium chloride; activated carbon

A QUANTUM CHEMISTRY STUDY ON THE SIZE-DEPENDENCE OF THE CHEMISORPTION OF AMMONIA AND CARBON MONOXIDE ON ALUMINUM CLUSTERS

The chemisorption intensities of NH_3 and CO on aluminum clusters A1_n(n=l-13) have been theoretically predicted by using CNDO/2 method and properly selecting the clusters' geometries.The results show that the chemisorptions of NH_3 and GO on Al_2,Al_6 and Al_12 are magically stable and thus are in good agreement with the experimental results.In addition,an electronic structure analysis is made to expound the nature of such a size effect.

Ammonia and greenhouse gas emissions from a subtropical wheat field under different nitrogen fertilization strategies

Minimizing soil ammonia（NH_3） and nitrous oxide（N_2O） emission factors（EFs） has significant implications in regional air quality and greenhouse gas（GHG） emissions besides nitrogen（N） nutrient loss.The aim of this study was to investigate the impacts of different N fertilizer treatments of conventional urea,polymer-coated urea,ammonia sulfate,urease inhibitor（NBPT,N-（n-butyl） thiophosphoric triamide）-treated urea,and nitrification inhibitor（DCD,dicyandiamide）-treated urea on emissions of NH_3 and GHGs from subtropical wheat cultivation.A field study was established in a Cancienne silt loam soil.During growth season,NH_3 emission following N fertilization was characterized using active chamber method whereas GHG emissions of N_2O,carbon dioxide（CO_2）,and methane（CH_4） were by passive chamber method.The results showed that coated urea exhibited the largest reduction（49%） in the EF of NH_3-N followed by NBPT-treated urea（39%） and DCD-treated urea（24%） over conventional urea,whereas DCD-treated urea had the greatest suppression on N_2O-N（87%） followed by coated urea（76%） and NBPT-treated urea（69%）.Split fertilization of ammonium sulfate-urea significantly lowered both NH_3-N and N_2O-N EF values but split urea treatment had no impact over one-time application of urea.Both NBPT and DCD-treated urea treatments lowered CO_2-C flux but had no effect on CH_4-C flux.Overall,application of coated urea or urea with NPBT or DCD could be used as a mitigation strategy for reducing NH_3 and N_2O emissions in subtropical wheat production in Southern USA.